A wide variety of electrical contacts for electronics modules are known. With respect to circuit boards that are operably connected to a base (such as a backplane, bus, etc.), the circuit board typically includes both power and data contacts located along a single edge of the circuit board that are adapted for mating with corresponding power and data connectors of the base. The circuit board is installed to the base by relative sliding movement between the circuit board and the base power and data connectors (typically by movement of the circuit board relative to the base) along an insertion axis that lies in the plane of the circuit board, with the edge of the circuit board including the power and data contacts being the leading edge in terms of the insertion direction. When the power and data contacts of the circuit board are operatively connected with the respective power and data connectors of the base, both the power and data connectors of the base are located adjacent the circuit board leading edge.
Such an approach for locating the circuit board power and data contacts along a single, common edge of a circuit board has been deemed suboptimal for a variety of reasons. For example, including both the power and data contacts on the single leading edge of the circuit board is challenging due to the space required for each and the limited space available on the leading edge of the circuit board. Also, regulations or design practices often specify a minimum required space between power and data contacts on the circuit board, and this makes it even more difficult to locate both power and data contacts on the leading edge.
Another issue that must be considered in locating the power and data contacts on a circuit board is the need to provide a contact system that enables removal and insertion under power (RIUP), where the circuit board or other electronic device is installed in or removed from a base while the backplane or other circuit of the base is actively transmitting data and also usually an operating voltage. Ideally, data continuity is maintained perfectly in the backplane circuit during the insertion and/or removal process. The known contact placements with both power and data contacts located on the leading insertion edge of the circuit board enable RIUP operations, and any viable alternative contact placement system must also be able to enable RIUP operations in order to be commercially viable.
FIG. 1 is schematic view of a conventional circuit board B′ as described above. The circuit board B′ includes one or more electronic components or circuits EL installed thereon or otherwise connected thereto, for example analog and/or digital input/output (I/O) electronics for an industrial automation I/O module. The illustrated circuit board B′ is rectangular and includes four edges E1,E2,E3,E4 that define its periphery P. Inner edge E1 is the leading edge in terms of the insertion direction ID along which the circuit board B′ is installed into a mating base X′. The base X′ is a complete backplane, housing, or like structure or a component same. The insertion direction ID extends parallel to an insertion axis IX that lies in the plane of the circuit board B′. The insertion axis IX is perpendicular to the inner edge E1. Outer edge E2 is spaced-apart from and arranged parallel to the leading edge E1, and first and second lateral edges E3,E4 are spaced apart and parallel relative to each other and extend between and interconnect the inner (leading) and outer edges E1,E2.
The base X′ includes power and data connectors PX′ and DX′ that are respectively connected to backplane/bus power and data circuits BX′ in the base X′. The circuit board B′ includes one or more power contacts PC′ and a plurality of data contacts DC′, and both the power and data contacts PC′,DC′ are located adjacent the inner edge E1 of the circuit board B′ and are located adjacent each other. The power and data contacts PC′,DC′ are adapted to mate respectively with the power and data connectors PX′,DX′ of the base X′. In particular, the power and data contacts PC′,DC′ of the circuit board B′ are operatively connected to the base power and data connectors PX′,DX′ via relative movement between the circuit board B′ and base X′ in the insertion direction ID (typically by movement of the circuit board B′ relative to the base X), and the power and data contacts PC′,DC′ of the circuit board B′ are operatively disconnected from the base power and data connectors PX′,DX′ with relative movement between the circuit board B′ and base X′ in the direction opposite the insertion direction ID. Field contacts/connectors F are located adjacent the outer edge E2 and/or one of the lateral edges E3,E4 and are adapted to be connected to field devices (e.g., sensors, switches, indicator lights, etc.) through a terminal base or removable terminal block (RTB) or otherwise.